Hardness testing apparatus



July 23, 1935. J. GOGAN HARDNESS TESTING APPARATUS Filed April 20, 1952 8 Sheets-Sheet. 1

July 23, 1935. J. QGOGAN 2,009,314

HARDNESS TEST ING APPARATUS Filed April 20. 1952 8 Sheets-Sheet 2 L| LI HARDNES S TESTING APPARATUS Filed April 20, 1952 8 Sheets-Sheet 3 y J. GOGAN 2,009,314

HARDNESS TESTING APPARATUS Filed April 20. 1932 8 Sheets-Sheet 5 July 23, 1935. J. GOGAN HARDN'ESS TESTING APPARATUS Filed April 20, 19:52 s Sheets-Sheet 6 July 23, 1935. J. GOGAN HARDNESS TESTING APPARATUS Filed April 20, 1952 8 Sheets-Sheet '7 l Hl HI Y Arrae/vsm July 23, 1935. J. GOGAN HARDNESS TESTING APPAfiATU Filed April 20. 1932 8 Sheets-Sheet 8 Patented July 23, 1935 UNITED STATES PATENT OFFICE 2,009,314 7 I 'HARDNESS TESTING APPARATUS Joseph Gogan,.Lakewood, Ohio Application April 20, 1932, Serial No. 806,367 43 Claims. (Cl. 265-14 This invention relates to new and improved testing apparatus, by means of which various bodies or articles. can be individually tested with great rapidity and accuracy, and without impairment of the utility of the bodies or articles. 7 As one of its objects this invention aims to'provide testing apparatus of the type having means for distorting a test piece by the application of a predetermined force thereto and embodying novel means for measuring such distortion.

.Another-object of this invention is to provide testing apparatus of improved form having means for indicating distortion produced in a test piece and embodying novel means for rendering the indicating-means effective and ineffective. j'

, Another object of this invention is to provide testing apparatus having relatively movable means for distorting a test piece and means for measuring the test piece distortion, and'wherein.

electromagnetic means is employed for rendering the measuring means responsive to the relative movement of the distorting means.

A further object of this invention, is to provide an improved hardness testing apparatus having an impression member which is'adapted to be 'moved into engagement with a test piece by a preliminary force and to be pressed into the test piece by a predetermined force in excess of the preliminary force, and wherein means for measur- 9o ing the movement of the impression member into the test piece, includes an indicator, anelectromagnetic means responsive to the applied force for operably connecting .the indicator with, and.

disconnecting the same from the impression mem- & .ber.

Still another object or this invention is to proa vide improved hardness testing apparatus having an impression member which is adapted to be actuated by fluid pres e, and also having novel ,fluid supply means to causing an initial rapid movement or the impression membeninto engagement -,with a test piece, and a subsequent relatively slow movement of the impression member into the test piece. J 45 It is also an obje'ct of this invention to provide improved, testing apparatus having a contact member for distorting a test piece and a cylinder for actuating the contact member, and embodyirig means for supplying motive fluid to the cylin- 50 der at a constant ratduring the' distcrtion of the test piece.

-Another object of the invention is to provide improved testing apparatus having a test piece distorting member and cylinder for actuating the j v section. g 5.

65 same by fluid pressure, and embodying means for a predetermined value.

ratus;

supplying pressure fluid to the cylinder at a constant rate during the distortion of the test piece and means for rendering'the pressure fluid supply means ineffective when the fluid pressure reaches 5 It is a further object of this invention to provide testing apparatus of the type referred to, which embodies novel control means rendering the apparatus automatic in operation, so that individual pieces can be tested in rapid succession'and with a 1 high degree of accuracy.

Other objects and advantages of the invention will be apparent from the following description, when taken in'conjunction with the accompany: ing sheets of drawings, wherein,

Fig. 1 is a front elevational-view of a testing machine embodying myinvention;

Fig. 2 is a side elevational view thereof Fig. 3 is a sectional elevation showing the impression member and gauge operating means,

taken substantially on line 3-4 of Fig. 1.

Fig. 4 is a sectional elevation taken substantially on line 4-4 of Fig. 1, and showing pressure responsive control means;

Fig. 5 is a sectional plan view taken on the line 5-5 of Fig. 2;

Fig. 6 is a vertical sectional view of .the fluid pressure supply pump, taken substantially on line 66 of Fig. 5; and Fig. 7.

Fig. '7 is a transverse sectional view of the 'pump taken on line 1--'I of Fig. 6;

Fig. 8 is a-sectional elevation of the pump actuating means taken substantially on line 8&-,of Fig. 5;

Fig. 9 is a partial elevational viewof the pump H actuating. means taken on line 9-9 of Fig. 5;

Fig. 10 is a sectional elevation taken through the pump. actuating means on line ill-Ill. of Fig. 5; I

Fig; 11 is an'elevational view of thepump actuating means with a portion of the transmission casing broken away to show the clutch operating mechanism; v f Fig. 12 is a diagrammatic view showing the electromagnetic control for the distortion indicator; j I

Fig. 13is a wiring diagram showing circuits for the pump operating motor and for manually controlling the, operation of the testing appa- Fig. His 9. partial elevationai view showing another form of testing apparatus embodying my invention, and

Fig. 15 is an elevational view thereof; partly in b Detailed reference will now be made to the accompanying drawings, wherein I have illustrated new and improved apparatus for rapidly and accurately testing individual bodies. In disclosing my invention 1 have illustrated what I now regard as a preferred form of my testing apparatus, but it should be understood, however; that my invention may be embodied in various other forms of testing apparatus. Before proceeding with the detailed description of the testing apparatus illustrated in the drawings, it is pointed out that, ingeneral, my invention provides for the testing of individualbodies or pieces by applying to each body, a force'of definite or predetermined value, and accurately measuring the corresponding distortion produced in the body. I am aware that various kinds of testing apparatus have been proposed heretofore, wherein measurement of the distortion produced in a test piece by a predetermined force has been attempted, but in the main such apparatus has been impractical, principally because of the inability of the apparatus to accurately measure the distortion produced in the test piece.

According to my invention, as will be explained in detail hereinafter, I provide electromagnetic means for rendering the measuring means responsive to the distortion produced in the test piece, and by this means I am able to obtain an instantaneous and very accurate indication of such distortion. My invention also provides a novel form of fluid pressure supply means, which makes possible a desired relatively rapid movement of a distorting member into engagement with a piece to be tested, and a subsequent relatively slow, but uniform movement of the member in distorting the test piece. As will be explained more in detail hereinafter, this electromagnetic means, as well as the novel fluid pressure supply means and the control therefor, enable an unskilled operator to perform accurate tests upon individual pieces in rapid succession.

In the embodiment of the invention illustrated in the drawings, I have shown a hardness testing machine which operates in conformity with the general principle ofthe Brinell test, wherein the depth of a recess produced in a piece of metal by pressing a spherical impression member thereinto, is proportional to the force required to produce the distortion. It-should be understood, however, that in my improved testing machine it is not necessary that the impression member be spherical in shape, but may be of other form or construction, such as a diamond pointed member. It should be understood, that although in this instance my invention is embodied in a hardness testing machine, it may, if desired, also be embodied in various other kinds of testing apparatus wherein the distortion produced in the material is proportional to the applied force, such as in apparatus for measuring compression, tensileand torsional characteristics of various bodies or materials. a

The hardness testing machine illustrated in the drawings is provided with a suitable frame 20, preferably, though not necessarily, of the gap type having supporting legs 2| and also having a test piece support 22. The test piece supporting means may be of a conventional type which is more or less diagrammatically shown in the drawings as comprising an anvil mounted on the upper end of a vertically extending adjusting screw. The adjusting screw is adapted to be rotated by means of the hand wheel 23 for varyingthe position of the anvil, and is adapted to be causes the ball desired position of adjustment by means, of the lock nut 24 through which'the screw extends. A suitable impression member, preferably in the form of a hardened spherical ball 25, is adaptedto' be moved into engagement with a test piece, such as the body 26 resting upon the support 22, by means of the movable ball holder or plunger 21. This plunger is mounted in the frame 20, above, and insubstantial vertical alignment with, the support 22, and is adapted for vertical sliding movement in the frame to move the ball toward or away from the test piece. The ball may be mounted on the plunger by providing the latter with retaining means of suitable form, such as the retaining chuck 28 shown in the drawings.

The portion of the frame in which the plunger 21 is slidably mounted is provided with a cylinder 29, into which the upper end of the plunger extends. A piston 30 is slidably mounted in this clamped in the cylinderandis rigidly clamped to the upper end of the plunger by means of the nut 31. The cylinder is closed at its upper-end by a cover 32, having a fluid pressure inlet fitting 33 for admitting motive fluid, such as a suitable oil, under pressure, to the cylinder to actuate the piston therein and thereby move the ball 25 into engagement with the test piece. Any suitable means may be provided for moving the ballin a direction away from the work, such as the coil spring 34 which is disposed around the upper portion of the plunger '21 and. engages the underside of the piston 30. This spring opposes downward movement of the piston and at the ball upwardly away from the test piece.

Fluid pressure is supplied to the cylinder 29 through a pipe 35 leading from the upper end of a pump 36. As will be explained more fully hereinafter, this pump is driven by an electric motor 31, through mechanism contained in the transmission casing 38 and including a clutch which is controlled by a solenoid 39. Without disclosing the detailed structure of the pump at this point of the description, it is pointed out that the pump is capable of supplying a large volume of motivefluid to the cylinder 29 at a suitable initial or preliminary pressure value, which may be approximately twenty pounds to the square inch, for rapidly moving the ball 25 downwardly'into contact with the test piece, and a relatively small volume of motive fluid, at a higher and progressively increasing pressure, but at a constant rate of delivery, for subsequently moving or pressing the ball into the test piece at arelatively slow, but uniform, rate. The initial pressure of approximately twenty pounds to the square inch, to be rapidly lowered into contact with the test piece, so that valuable time will not be lost in bringing the ball into position for making a test.

The higher subsequent pressure applied to the ball, causes the latter to distort the test piece by being depressed into the material of the piece at a slow, but uniform, rate. The rate of movement of the ball will be different for different materials, and may be different for each of several pieces of the same material, but according to my invention, the rate of travel or velocity of the ball will, in each test, be uniform throughout the full distance that the ball moves into the test piece. I find that by providing for such a slow, but uniform, movement of the ball into the piece, the test readings are not rendered inaccurate, as by the inherent resilience, or other characteristic of the material being tested, such as the tendall times tends to move ency for'the material to flow or burr up around I the ball.

- mounted in the plunger For indicating or measuring the extent of movement of the ball 25 into the test piece, I employ a suitable gauge 43 which is mounted upon the frame of the machine. This gauge may be of any desired form and, in this instance, embodiesa movable pointer 4|, which is adapted to be rotated'in one direction by downward move ment,of a stem 42 projecting from the casing oi the gauge, and to be rotated in the opposite di-'- rection by'a spring which is contained within the gauge housing and normally tends to oppose downward movement of the stem. According to my invention, I provide means for operatively connecting the gauge stem 42 with the plunger 21 at the instant that the ball begins to enter the test piece, and for disconnecting the stem from the plunger and temporarily locking the gauge pointer for reading by the operator when the force applied to the ball reaches a predetermined or definite value.

In the drawings, I have shown this gauge operating or control means as including an elongate ed relatively thin strip 43 of magnetizable material, which-is loosely connectedto the lower end of the stem 42, and which extends downwardly between the oppositely disposed electromagnets 44 and 45. The magnet 44 is arranged for movement with the plunger 21, preferably by being adjacent the lower end thereof. The electromagnet 45 is stationarily mounted in an opening in the supporting member 46 which is secured to the frame 20. These electromagnets may be of any suitable form of construction, and in this instance, the magnet 44. is shown as having a magnetizable core 41 surrounded by a winding 48, and as having an outer casing 49, preferably of non-magnetic material, the entire magnet and outer casing assembly being retained in an opening provided in the plunger 21 by a clamping nut 50 applied to one end of the core. The electromagnet 45 is similarly constructed, being provided with a magnetizable core 5|, which is surrounded by a winding 52. As shown in the drawings, this magnet may be retained in an outer, preferably non-magnetic, casing 53 mounted in an opening of the support 46, {by means of anut 54 applied to the the outer end of the core 5|. r

The magnetizable member 43 is made sumciently long to extend down past the adjacent ends of the magnet cores 41 and 5|, so that it can be swung laterally in either direction, as seen in Fig. 3, byenergizing one orthe other of the magnets. When the ball '25 is moved downwardly into contact with the test piece by the preliminary pressure, the magnet 44 is energized, by means to be explained hereinafter, thereby causing the member to be drawn toward'the core 41. The movementof this member, under the influence of the core 41, causes it to be tightly held against the face of the outer casing 49 and, in a sense, to

be connected with the plunger 21. Thus the casing 43 constitutes an abutment means against which the gauge operatmg. member 43 is releasa bly clamped by the magnet 44.

' As the plunger continues its downward move- .ment to press the ball 25 into the test piece, the member 43 moves downwardly with the plunger, thereby causing the stem 42 to be moved downwardly and the pointer of the gauge to be ro-,

tated. When the force being exerted upon the ball reaches a predetermined value, the magnet 45 is energized by control means, which will ber 43' from the plunger. It should be stated at this that it is capable of producing a considerably stronger magnetic field than the magnet 44, and when the winding 52 is energized the member 43 will be attracted away from the magnet 44. The movement of the member 43, under the influence of the magnet 45, causes this member to be disconnected from the plunger 21 and to be tightly held against the. inner face of the outer casing member 53, thereby locking the gauge stem 42 against being retracted by the-spring within the gauge housing, and thereby locking the pointer of the gauge at the setting thereof corresponding with the predetermined pressure exerted on the ball. While the magnet 45 remains energized the pointer of the gauge is locked against movement in either. direction, and its position at this time is noted by the operator, fromwhich reading or indication the hardness characteristic of the;

piece being tested, may be determined.

For controlling the energization of the magnets ing 38. The casing 51 is provided with a cylinder 58, to which fluid pressure is-supplied from the pump 36 through a connecting pipe 59. A plunger is slidably fitted in the cylinder 58 and has a stem 6|, which extends upwardly through the cover 62 into a housing 63, the latter forming a part of a switching device mounted upon the cover. larged to form a chamber 64, through which the stem 6| extends. A coil spring 65 is disposed in this chamber in surrounding relation to the stem 6| and with its ends in engagement, respectively, with the cover and with a shoulder 66 located at the junction of the stem with the upper end of the plunger 60. This spring normally maintains the plunger in its lowermost position with the shoulder 66 acting as a stop to limit the v downward movement of the plunger.

At the upper end of the stem 6| I provide a suitable contact 68 which is carried in a sleeve .69, the latter being mounted on the upper end of the stem but insulated therefrom by the in-. sulating bushing 68'. This contact member is preferably threadedly connected to the sleeve 63' so as to'be adjustable relative to the stem, and may be retained in the desired position of. adjustment by means of the clamping nuts 10.,

- The contact member 68 cooperates with a contact member 1| whichis carried by a sleeve 12, the latter being slidably mounted in a housing 13 which is insulated from the housing 63 by a suitable insulating body 14 interposedtherebetween. A cofl spring 15 is disposed around the sleeve andnormally maintains the contact member 1| in its lowermost position with the bottom of the sleeve engaging the abutment 16. The sleeve is provided at its upper end with an opening 11 leading to the hollow interior of the sleeve. A contact member 18 extends through the opening "and is formed with a body portion 19, which is slidable within the sleeve. A coil spring 86 is' int, that the magnet 45 is so constructed.

The upper end of the cylinder 58 is entains the body portion 19 in engagement with the upper end of the sleeve with the contact member 18 extending outwardly through the opening 11, as shown in Fig. 4 of the drawings.

A stationary contact member 82 is mounted in the housing 13 above the contact member 18, and is adapted to be engaged by the latter. The contact member 82 is insulated from the housing, as by means of the insulating bushing 83, and is provided at its upper end with a threaded terminal to which a conducting wire 84 may be attached. A similar conducting wire 85 extends through an opening in the wall of the housing 63 and is attached to the contact member 68, and a third conductor 86 is attached to the housing 13 which, as pointed out above, is insulated from the contact member 82 and from the contact member 68.

As diagrammatically shown in Fig. 12, the conductor 84 isv connected to one end of the winding of the electromagnet 45, and the conductor 85 is connected to one end of, the winding of the electromagnet 44 through a contact device 81 which will be presently described. As shown in ,Figs. 3 and 12 of the drawings, the opposite ends of the winding of the electromagnets 44 and 45 the frame of the machine by being connected to screws 88 extending into the outer casings of the magnets. The conductor 83 is connected to any source of electric current of suitable characteristic, and in this instance, I connect this conductor to a source of non-pulsating current, such as to one terminal of the storage battery 89. The opposite terminal of this battery is grounded to the frame of the machine so that energizing circuits may be established through the windings of the electromagnets 44 and 45.

The coil spring 65, and the cross-sectional area of the plunger 60, are so proportioned that the spring will prevent upwardmovement of the plunger whenthe latter is subjected to only the preliminary pressure supplied by the pump for moving the impression member 25 into engagement with the piece to be tested. The spring and are grounded to plunger are so designed, however, that when the fluid pressure begins to increase, by reason of the resistance which the test piece offers to the downward movement of the ball 25, the plunger immediately responds to the pressure increase and moves upwardly against the action of the spring and causes the contact 68 to engage the contact 1I, whereupon current flows from the battery throughthe conductor 88, the contacts H and 88 and through conductor 85 to the winding of the electromagnet 44. Energization of this electromagnet causes the gauge actuating member 43 to be clamped to the plunger 21 for movement therewith. As the ball 25 continues to move into the test piece, the plunger 60 continues to move upwardly, and when the fluid pressure increases to the predetermined definite value required to compress the springs 65 and 15 sufflciently to ,cause the contact 18 to engage the contact 82, which may be a pressure of five hundred and fifty pounds per square inch, current thereupon-flows from the battery through the contacts 18 and 82 and the conductor-84 to the winding of the electromagnet 45. The energization of this winding causes the gauge actuating member 43 to be attracted away from the plunger 21 and to be stationarily held against the casing 53, as explained above, whereupon the operator notes the position of the pointer oi the gau e 40.

i Since the electromagnet 44 moves with the plunger 21, it may be desirable to supply current to this magnet through a contact device, such as the contact device 81 shown in Fig. 3. This contact device comprises a contacting plate or strip 90, carried by the plunger 21 and to which one end of the winding 48 is connected, and a contact roller 9| which engages the conducting strip. This roller is carried by an arm 92 which is pivotally mounted on the insulated-housing 93. A coil spring 94 is interposed between one end of the arm 92 and the wall of the housing 93 for pressing the roller'against the contact strip and to form an electrical connection between the insulated housing and the pivoted arm. The conductor 85, which is connected to the contacts B8,

may be connected to the housing 93 as by means v of the screw 94.

The housing of the control unit is also provided with a cylinder 95 which communicates with cylinder 58 through the passage 98. The cylinder 95 is of somewhat larger diameter than the cylinder 58 and is fitted with a slidable plunger 91. This plunger is provided with a stem 98 which projects into an enlargement formed at the upper end of the cylinder 95. A coil spring I00 is disposed around the stem 98 and engages-a laterally extending shoulder or flange IOI provided on the plunger, and normally tends to move the plunger downwardly in its cylinder, such downward movement being limited by the shoulder IOI engaging the bottom of the enlargement 99. The spring I00, and the cross-sectional area of the plunger 91, are so proportioned that the plunger will be moved upwardly, by the pressure of the motive fluid which causes the ball 25 to be pressed into the test piece, thereby utilizing some of the pressure fluid and maintaining the downward movement of the ball at a relatively slow rate. Movement of this plunger in opposition to the force of the spring also causes this plunger to functionas asurge absorbing device, which takes up or absorbs pulsations which may occur in the pressure fluid being delivered by the pump.

The casing 51 of the control unit is provided with a third cylinder I03, inwhich a plunger I84 is slidably fitted. The upper portion of this cylinder is enlarged to provide a chamber I05, into which the stem I06 of the plunger I04 extends. A spring I01 is disposed in the chamber I05, so as to surround the stem and to normally move the plunger downwardly in the cylinder by cooperating witha laterally extending shoulder or collar I08, which functions as a stop for limiting such downward movement of the plunger. The stem I06 preferably extends upwardly through the cover 62, as shown in Fig. 4 of the drawings, and cooperates with the actuating membet I09 of an electric switch] I0 which is disposed in the circult of the solenoid 39. The switch I I0 is so constructed that it is normally closed, but when opened-by upward movement of the actuating member I09, it causes the circuit of the solenoid 39 to be opened. As will be explained more fully hereinafter, the opening of the solenoid circuit terminates the power stroke of the pump to thereby cut off the supply of pressure fluid to the cylinder 29 and to the control unit 55.

It will be noted from the arrangement illustrated in Fig. 4, that pressure fluid is not supplied directly to the cylinder I03 from the pump 36, but -is supplied to this cylinder through a pipe I I2 which leads from a recess I'I3 formed in the easing 51 around the plunger 60. The plunger 60 is so proportioned as to length that .it extends.

the recess II3, it will be .moved downwardly by the :in this position, fluid through the recess I I3 and cooperates with the wall thereof in the manner of a valve to control the flow offluid into the pipe II2. In thus supplying pressure fluid to the cylinder III3 through seen that the plunger I cannot be actuated to open the circuit of the solenoid until after the plunger 60 has been moved upwardly enough to cause the pairs of contacts 63, II and 18, 82 to be closed in succession to energlze'the electromagnets 44 and 45. Since actuating fluid is not supplied to the cylinder I03 until after the contacts 68 and 13 have been moved into engagement with the contacts H and 92, it will be seen that the solenoid 39 will not be deenergized to terminate the supply of pressure fluid until after the ball 23 has been pressed into the test piece and the operator has had an opportunity to read the gauge 40.

After the solenoid 39 has been upward movement of the switch the supply of pressure fluid has deenergized by member I09 and been terminated,

the plunger 60 will move downwardly under the action of the spring 65 and prevent further flow of fluid in either direction through the pipe II2. To relieve the pressure trappedvin this pipe and in the cylinder I33, so that the plunger I04 may be spring I01, I provide a relief Passage H4 which communicates with the cylinder I63 and with the bore of the cylinder 95,

through aport 5. To enable the plunger 91 to.

cooperate with the port I I5 in the nature of a valve. I provide the plunger with an annular recess II6 which registers with this port when the plunger is in its lowermost position, as illustrated in Fig. 4. When the plunger is cylinder I93 through the passage I I4 to the annular recess H6, and thence into the chamber 39 through a passage I I1 which extends upwardly through a portion of the body of the plunger. It will be seen from the arrangement just described that when dot to press the ball 25 into the test *piece, the same fluid pressure acts upon the plungers 60 and 91 of the control unit. As this pressure increases and moves the plunger 60 upwardly, to thereby actuate the contacts wand 10 and to allow fluid to pass through the pipe II2 to the cylinder I03 the plunger 91 is also moved upwardly by the fluid pressure and closes the port H3. The plunger Ill, then being subjected to the pressure of the motive fluid, is moved upwardly to open theswitch III. The opening of this switch causes the pressure fluid supply to he cut of! allowing the plungthe action of the springs 65 and I09. The down-- era 69 and 91 to descend in their cylinders under ,ward movement of the, plunger 91 brings the annular recess H6 into registry with the port H5,

thereby relieving the pressure trapped in the cyl-I 60 inder I63 by placing this cylinder in communication with the chamber 99. now to the fluid pressure supply unit previously referred to as comprising the pump' 36, motor 31 and transmission 36, it will be noted that this unit is designed to be compactly mountedupon the frame 2901? the testing machine. however, this unit may occupy any ings', the pump of the pressure supply unit is of the reciprocating type and is provided with a vertically elongated,

the transmission casing 33. The housing H9 is closed at its upper end bya cover: I 23 having a plunger I2I thereon to extend into 35 and 69 for delivery, inder 29 and the control unit 56. The opening.

may pass from thev ball I32. Upon upward pressure fluid is supplied to the cylintending through the plunger "I.

that asthe cylinder I29 the pinion I34, I the grooves I36 and the passage I26, for desubstantially cylindrical outer housing II9, which maybe supported upon the casing. The plunger is mounted'upon the cover by providing the hollow plunger stem I22, with a shoulder. I23, for engagement with the underside of the cover, and with a threaded portion I24 which extends operation with the hollow clamping nut I25. The opening in the stem I22 a discharge passage I26 which communicates with the hollow interior of the nut, and through which pressure fluid may be supplied to the pipes respectively, to the cylin the stem also extends downwardly through the plunger I2I to form a. cylinder I 21 of small diameter, in which a plunger I 28 of correspond-- ingly small diameter is slidable. The plunger through the cover for 00- provides the pump with I28 is mounted within a larger cylinder I29, which is slidable within the outer casing II 910T cooperation with the stationary plunger I2I. The plunger I23 is preferably mounted within the cylinder I29 by providing the plunger with a supporting stem I30; This stem extends downwardly in the movable cylinder I29and is secured to the lower end of this cylinder by means of a suitable connection I,3I which, in this instance, also forms a cage for the check valve ball I32. I

The cylinder I29 is provided on its outer surface with a rack I33, which is engaged by the pinion I34, so that upon rotation of the pinion in one direction or ,the other, the cylinder may be moved upwardly or downwardly within the outer casing 'I I9. Fluid is admitted to the cylinder l29, as the latter is moved downwardly, through a passage I35 which is controlled by the I movement of the cylinder fluid is forced outwardly into the delivery passage I26 through one or more longitudinal rooves I36 formed in the inner wall of the cylinder I21 adjacent the lower end thereof. As the cylinder I28 is moved upwardly with it, and fluid will continue to be forced outwardly through the grooves I36, until the top of the plunger I28 overlaps the upper ends of these grooves and closes the same, whereupon communication between the passage I26 and the interior of the is forced outwardly through the passage I26 prior to the closing of the grooves I36 by the plunger I28, I provide a pressure regulating means in the nature 'ota check valve, comprising a valve member I31 which is disposed around the stem I22 and is slidable thereon for cooperation with' a plurality ofpassages I33 exs .valve member ls nonnally'held against the plunger by means of a coiled spring I39, which is disposed around the stem I22. The spring I39 and the cross-sectional area of the passages I38 are. so proportioned that the valve member I31 will be lifted bythe .fluid pressurewhen the latter, reachesthe value desired for the preliminary pressure, which may be approximately twenty pounds to the square inch. Thus it will be seen 66 at the preliminary pressure value. Should there be a tendency toward an increase in this pressure value, the valve member I31 will 1 be unscated and some of the fluid in the cylinder I29 will be forced upwardly through the passages is moved upwardly by ward movement of the cylinder through the passage sequent relatively 'ber I49 is carried by a 6 I38 into the chamber I40 formed in the upper portion of the housing II9.

After the cylinder I29 has been moved upwardly through a sufficient distance to cause the plunger I28 to close the grooves I36, the delivery of fluid to the cylinder 29 at the preliminary pressure value is cut off, and as the cylinder continues to move upwardly the plunger I28 begins to act upon the fluid in the cylinder I21 and in the passage I26. It should be noted at this point that the diameter of the cylinder I29 is relatively large. as compared with the diameter of' the plunger I28, and consequently the initial upcauses a relof fluid to be forced out I26, whereas the upward movement of the plunger I26, subsequent to the closing of the grooves I36, causes only a small volume of fluid to be forced outwardly through the passage I26. Delivery of a large volume of fluid at the preliminary pressure value is desirable, as explained heretofore, for causing an initial rapid movement of the ball 25 into engagement with the piece to be tested. The subslow movement of the ball 25 into the test piece is obtained by the action of the plunger I28 in forcing a relatively small volume of fluidoutwardly through the passage I26 at a high pressure.- It will be understood, of course, that the relative area of the plungers I2I and I28 may be varied in accordance with the different pressurevalues or volumes which may be desired.

Since the closing plunger I28, cuts off communication between the cylinder I29 and the passage I26, the fluid remaining in the cylinder performs no further function, and to provide for the escape of this fluid without requiring the expenditure of work in moving. the valve member I31, I provide one or more grooves I42 in the inner surface of the cylinder I29. These grooves extend for the major portion of the length of the cylinder, so that immediately after the plunger I28 closes the grooves I36, the grooves I42 will be opened above the plunger I2I, to thereby provide direct communication between the cylinder I29 and the chamber I40. As the cylinder I29 and plunger I28 continue to move upwardly, fluid' will flow freely from the cylinder I29, through'the passage I42 into the chamber I40. To allow the fluid to leave the chamber I40, I provide one or more grooves I43 in the outer surface of the cylinder I29, as shown in Figs. 6 and '1 of the drawings.

atiyely large volume The grooves I43 extend for the full length of the cylinder, so that the chamber I40 will always be in communication with the oil reservoir or cylinder I44 formed by the lower portion of' the outer casing Il9.

To provide for the desired reciprocation of the cylinder I29 by the pinion I34, I employ suitable mechanism which is housed in the transmission casing 38, and which is driven by the motor 31. This mechanism includes a drive shaft I46, to

. which the pinion is keyed, and which is rotatably the casing 38 by suitable bearings I41 and I48. Intermediate the bearings I41 and I40, this shaft forms a support for a pair of rotatable clutch members I49 and I50, and for a clutch member I5I which is slidably splined to the shaft for selective cooperation with the clutch members I49 and I50. The clutch memsupported in in turn, carried by a worm gear I53. The spur gear and worm gear are rotatably journaled on of the grooves I36 by theshaft I06 to be driven in a spur gear I52, which is,-

the shaft I46, with the worm gear meshing with a driving screw I54. This screw is rotatably supported in the housing by suitable bearings I55 and I56, and is driven from the motor 31 through spur gears I51 and I58. The spur gear I52 meshes with a spur gear I59, which is drivingly secured to a countershaft I60. A spur gear I6I is secured to the opposite end of the countershaft and meshes with an idler spur gear I62. The idler gear I62 meshes with a spur gear I63 which is journaled upon the shaft I46 and to which the clutch member I50 is secured. It will be seen from the arrangement of gearing just described, that as the motor 31 operates continuously in one direction, the clutch member I49 will be driven in onedirection at a desired speed, while the clutch member I50 will be driven in the opposite direction, and by moving the clutch member I5I into engagement with one or the other of these rotating clutch members, the pinion I34 will be rotated to move the pump cylinder in the desired direction.

As stated above, it is essential to the accuracy of my testing apparatus that the test ball be moved in into the material of the test piece at a slow rate and also at a rate which is absolutely uniform. Inmy testing apparatus I attain the desired slow rate of movement of the ball into the test piece, by the novel form of pump structure just described, and attain a uniform movement of the ball into the test piece by employing a synchronous motor, as the electric motor 31, which drives the pump 36. It is characteristic of a synchronous motor that the driving speed is constant for variable loads within the rating of the motor, and in my testing machine the synchronous motor 31 drives the plunger I28 at a uniform rate of speed and causes pressure fluid to be supplied to the cylinder 29 at a constant rate, with the result that the ball 25 is moved into each test piece at a velocity or rate of speed that is uniformfor the full travel of the ball into the piece.

Any/suitable means may be used to actuate the clutch member I5I, and in this instance I provide aforked lever I65 having operative engagement with the movable clutch member, and a lever I66, which cooperates with the solenoid 39,

and which actuates the forked lever through the rock shaft I61. The lever I66 may be connected to the solenoid in any suitable manner, but I prefer to form this connection by providing the solenoid plunger with a stem I69, which extends through the lever. To connect the lever I66 with the stem I69 in such a manner as to permit limited relative movement therebetween, I provide a pair of coil springs I10 and I1 I, which surround the stem and are disposed on opposite sides of the lever. The compression of these springs may be adiustably varied by moving the nut- I12 toward or away from the shoulder or abutment I13. If desired, the lower end of the solenoid stem I69 may be extended to cooperate with the guide bearing I14, for guiding the reciprocating movements of this stem.

When the solenoid 39 is energized, the stem I69 is lifted, causing the lever'l66 to rock the shaft I61 and thereby swing the forked lever I65 with the result that the clutch member I5I is shifted to the right, as seen in Fig. 8, into engagement with the clutch member I49. The engagement of these clutch members causes the direction to raise the pump cylinder I29 to thereby deliver pressure fluid to the cylinder 56. When the switch I I0 is opened and the sole- 29 and to the control unit member I50 causes the shaft I46 to be rotated in the opposite direction, or, other words, in a direction to cause the pump cylinder I29 to be lowered. A

When the pump cylinder approaches its lower- .most position, it is necessary that the clutch member I5I be moved out of engagement with.

the clutch member I50 and into a neutral position-intermediate the clutch members I50 and I49 preparatory to the next power stroke of the pump. To this end I provide a cam I15, which Fig. 11.

is arranged to engage the lever I66 to shift the'clutch member to. the neutral position. The cam I is carried by a spur gear I16, which is driven from the pinion I34 through an idler gear I11, as shownin Fig. 11 of the drawings. With the clutch member I5I in its neutral position, as shown in Fig. 8, the cam I15 and the lever I66 cccupy substantially the position illustrated in As the pump cylinder I29 is moved upwardly by the pinion I34, the cam travelsin a clockwise direction, as seen in Fig. 11, and moves away from the lever. This cam, and the .driving gears therefor, are so designed that the upward travel of the pump cylinder will be stopped by the opening of the solenoid circuit before the'face I18 of the cam engages the top edge of the lever I66. As the pump cylinder I29 is moved downwardly by the rotation of the pinion I34 in the opposite direction, the cam I15 is rotated in a counter-clockwise direction, as seen in Fig; 11, and as the pump cylinder approaches its lowermost position the face I19 of the cam engages the underside of the lever I 66 and lifts the latter to throw the clutch member I5I out of engagement with the clutch member I50 and into the neutral position illustrated in Fig. 8. Inconnection with the actuation of the lever I66 by means of the cam I15, it is pointed out that the weight of this lever and of the solenoid plunger and stem I69 are so propor- 'tioned, relative to the counterweight I80, that when the solenoid is deenergized the bell 'cr'ank lever will, of itself, shift the clutch member I5I out of engagement with the clutch member I49 and into engagement with theclutch member 150. When the lever is engaged by the face I19 of the cam I15, the weight 01' the lever and of the solenoid plunger and stem prevents the clutch member I5I from being shifted back into engagement with the clutch member I49, and

causes the lever to come to rest substantially in the position shown in Fig. 8, with the clutch member I5I 'in its neutral position. I

After a hardness test has been made and the solenoid 39 has been 'deenergized to cause the fluid pressure supply-to-be cut off, the spring 34' causes the piston 30 to be moved upwardly, thereby forcing fluid back to the pump through the pipe 35. Likewise, some of the fluid delivered to the control unit is returned to the pump through I the pipe 59 bythe action of the springs- I00 and 65. however, during the operation of the control unit as previously explained, some of the fluid is admitted to the chamber 99 through the passage II1. To return this fluid to the pump,.

' as well as any fluid which may have leaked'into thechambe'rs -64 and I05, I provide a return pipe I82 which communicates directly with the chamber 64 and with the chambers 99 and I05 through. the passages I83 and I84. If desired, the pipe I82 may be arranged to communicate directlywith the cylinder I44 of the pump, but

I prefer to connectthis pipe with the transmissicn casing 38 which, as shown in Fig. 5, communicates directly with the cylinder I44 of the outerpump. casing II9. I

The supply of fluid contained in the system may be replenished by removal of the filling plug I85 of the transmission casing 38 and the intro-,,

netic switch I90. This switch is of conventional form, and. is provided with start and stop buttons'I9I and I92 for controlling theclosing and opening of the contacts I89 whenit is desired -to startor stop the motor. During ordinary use of the testing machine, the .motor 31 is started by pressing the button I9I and is allowed to run' continuously during the work period devoted to the testing of pieces.

To enable the operator to energize-the solenoid 39 ,when a piece is to be tested, I provide a control switch, preferably in the form of a foot switch l93, having a contact member I94 which is normally held in engagement with the contacts I95 by the spring I 96. While the'contact member I94 remains in engagement with the contacts I95, the winding I91 of an electromagnet I98 remains energized. The circuit for the winding I91 may be traced from the power conductor I99, through the contact member I94 and the conductors 200 and 20I,' to the windingl91 and thence to the power conductor 202." When the winding I91 is energized, the contact members 203 and ,204 of the switch I 98 are moved into engagement, re-

spectively, with the contacts 205 and 206. The.

winding l91 may be traced from the power conductor I99, through the conductor 201,- through the contact member 204;and the conductor 208 and through the contact member 209 of the normally closed solenoid switch I I 0, and then through conductor 20I to the winding I91 and thence to' the power conductor 202.

When the foot switch I93 isvdeprsseu by the operator to make a test, the contact member I94 moves out of'engagement with .the contacts- I95 and the contact member 2 I 0 is thereby moved into engagementwith the contacts 2| I. The engagement of the contact member 2 I0 with the contacts 2 causes the winding 2I2 of an electromagnetic switch M3 to be energized;. The circuit for-this winding may be traced from the power conductor- 202, through the contact member 203, which has;

been previously closed by the energizing of the' winding I91, through the conductor 2I4 to the winding 2I2, and thence through conductor 2I5' and contact member 2I 0, back to the power conductor I 99, The energizing of the winding 2I2 of the switch 2I3 causes the contact members'2 I6 and 2" of this switch to be moved, respectively,

into engagement with the contacts. 2| 8 and 2I9,

to thereby close the circuit which includes theinto engagement with the clutch member I49 to move the pump cylinder upwardly in the manner already described.

To provide for deenergization of the solenoid 39 after a piece has been tested, and to prevent the solenoid from being reenergized should the operator neglect to take his foot off the switch I93, I employ an automatic control which requires proper manipulation of the foot. switch I93 to obtain actuation of the ball 25 for the testing of successive pieces. This automatic control includes a contact member 220, which is moved into engagement with the contacts 22I by the energization of the winding of the switch 2I3. engagement of the contact member 220 with the contacts-22I causes the winding 2I2 to remain energized so long as the winding I91 of the switch I98 remains energized and the switch IIO remains in the closed position. This auxiliary energizing circuit for the switch 2I3 may be traced from the power conductor I99, through contact member 220, conductor 222, contact member 223 of the normally closed switch H0, and through conductors 224 and 2I5 to the winding 2I2 and thence through conductor 2 I4 and contact member 203 to the power conductor 202.

From the circuit arrangement just described it will be seen that as soon as the stem I09 of the control unit causes the switch IIO to be actuated and the contact members 209 and 223 thereby moved to the open position, the winding I91 and the winding 2I2 will be deenergized. The deenergization of the winding 2I2 allows the contact members 2I6 and 2" ingthe winding of the solenoid 39 to be 'deenergized. The d'eenergization of the winding I91 likewise allows the contact members 203 and 204 to which a test ball is to drop open, with the result that the circuits for the windings I91 and 2 I2 are so altered that these windings cannot again be energized until the operator has allowed the contact member I94 to be moved into engagement with the contacts I95 by the spring I96. After the winding I91 has been energized by the release of the-foot switch, the winding 2 I 2 may then be energized by depresssolenoid 39. The circuit for the The.

to drop open, thereby caus the rod 232 may be prevented ing' the foot switch to cause the contact member whereupon the 39 is energized by the closing of the switch 2I3 to cause the desired operation of the machine.

It will be seen from the foregoing description, that" during the operation of my hardness testing machine the reading or. indication obtained from the gauge 40 represents the extent to which the test ball 25 is pressedinto a test piece by a definite or predetermined pressure value. It is a wellrecognized law of physics that the hardness of a material is directly proportional to the depth forced into the material by a definite pressure, and it will thus be seen that the readings obtained from the gauge 40 indicate directly the hardness of the pieces being tested.

As the individual pieces of unknown hardness are. tested, the operator notes the position of the gauge pointer, relative tea reference character between the movable magnet 230 and the or line representing a certain hardness value,

and if the pointer stops short of this reference character, the operator will know that the piece is harder than required, and if the pointer moves beyond the reference character he will know that the piece being tested is softer than it should be. Knowing the amount of permissible variation in the hardness of the pieces relative ,to a desired hardness for the character of material being tested, the operator is able to determine directly from the gauge indications which pieces are to be rejected as unsatisfactory. From time to time during the operation of the machine, it may be desirable to have the operator insert a standard test piece of known hardness, and make a test thereon for the purpose of checking the accuracy of the machine.

InFig's. 14 and 15 of the drawings, I have shown a hardness testing machine which operates on substantially the same principle as the machine just described, but wherein the electro-magnets for controlling the operation of the indicating gauge are arranged somewhat differently. As shown in Fig. 15, .a movable magnet 230 isconnected to the plunger-2M which actuates the test ball (not shown) by means of a stem or rod 232 which passes through the cover 234 of the fluid pressure cylinder 235. Leakage of fluid around by use of a suitable packing gland 236. A magnet 231 is 'stationarily arranged above the highest point of travel of the magnet 230 by being mounted in a support or bracket 238 which may be mounted upon a convenient portion of the machine, such as the cylinden cover 234.

A gauge 239 of suitable construction, is mounted upon the bracket238' above the stationary magnet 23?. This gauge is provided with a movable pointer 240 and an' outwardly extending movable stem 24I, and also embodies a spring which normally tends to cause rotation of the pointer and downward movement of the stem 24I. A magnetizable member 242 is pivotally connected to the stem 24I and extends downwardly past the core 243 of the magnet. This member bears against the lever 244, which extends through an opening provided in the bracket 238, and is pivoted to the bracket by means of thepin 245. The lever 244 is provided with a slidable counterweight 2.45, which is so adjusted that the force resulting from the normal tendency of the gauge spring to move the member 242 downwardly, is slightly exceeded, with the result that the gauge pointer is normally' returned to the zero position by the action of the pivoted leverovercoming the gauge spring. a

At or adjacent the end of the lever 244, against which the magnetizable member 242 bears, I provide a second magnetizable member 241 which is pivoted to the lever and extends downwardly bracket 238. When a hardness test is being made with this machine, motive fluid of a desired pressure value is admitmd to' the cylinder 235 through the pipe 248. Some of the motive fluid is also admitted to the cylinder of the control device 249 through the pipe 250. When the pressure of the fluid reaches a predetermined value it causes upward movement of a plunger contained in the control device 249 to thereby move the contact member 25I upwardlydnto engagement with a contact member 252. The closing of these contact members closes causing the winding of this magnet to be energized from the battery 253. .The energization of the circuit of the magnet 230,

the magnet 230 causes the magnetizable member 241 to be attracted; and thereby connected. for

movement with the-plunger 23 I. As this plunger it and causing the latter to engage the contact member 254. The engagement of the contact member 252 with the contact member 254 closes the circuit of the stationary magnet 231, so that energizing current will be supplied thereto from the battery 253. The energization of the magnet 23! causes the magnetizable member 242 to be attracted and thereby held or locked against movement in either direction. The operator now observes the position oi. the pointer of the gauge, which enables him to compare the hardness of the piece being tested with the hardness of a standard test piece. In carryingout a test in the manner just described motive fluid of predetermined pressure value may be supplied to the cylinder 235, and to the control unit-249, from any suitable source, *such as the pump 255.- At the completion of the test the pressure of the motive fluid is relieved, as by controlling the operation of the pump 255, thereby allowing the contacts 25l and 252 to be moved downwardly to their open position, as shown in Fig. 14. The opening of these contacts deenergizes the electro-magnets 230 and 231,

thereby releasing the magnetizable members 242 and 241 and allowing the gauge pointer to return to its zero position. It desired, the fluid pressure supply means may include a reservoir 256 for maintaining the system charged with fluid, and a pressure regulator 251 for obtaining the desired predetermined pressure value. Likewise, a suitable pressure gauge 258 may be employed to enable the operator to determine from time to time whether or not the proper pressure is being applied to the ball actuating plunger 23L It will be readily understood from the foregoing description, that I have provided a novel form of testing apparatus which is extremely accurate; and which is capable of testing indi- 'vidual pieces in rapid succession. It will also be noted that in the testing apparatus disclosed, the synchronous motor will operate at substantially uniform speed-regardless of load, so that the ball will be pressed into the test piece at an absolutely uniform'rate, and error due to characteristics of the metal being tested, will be entirely eliminated. Moreover, it will be seen that the electro-- magnetic control means which I have devised for controlling the actuation of the gauge, provides for extremely accurate functioning of the machine. It will also be noted that the fluid pressure supply means which I employ, provides efllcient and compact means for causing an initial rapid movementof the impression member into engagement with the test piece, and a subsequent slow, but uniform, movement of the impression member into the metal at the piece being tested. It is also characteristic of my testing machine that I provide an efficient and reliable form of control which is largely automatic in operation, malging possible the successful use of the machine in factories employing unskilled labor.

-While I have illustrated and described the testing apparatus of my invention in adetailed man ner, it should be understood, however, that I do not intend to limit myself to the precise details of construction and arrangements of, parts illustrated and described, but regard my invention as including such changes and modifications as do 9 not involve a departure, from the spirit of the invention and the scope of the appended claims.

Having thus described my invention, I claim:

1. In testing apparatus of the character described the combination of a support for a test piece, a contact member adapted to be applied to said test piece, means for causing relative movement between said contact member and said support to thereby distort said test piece, an indicator, means for rendering said indicator responsiveto said relative-movement, and means for rendering the indicator non-responsive to the relative distorting movement when the force applied to the test piece reaches a predetermined value.

2. In testing apparatus of the character described the combination of a support for a test piece, a movable contact member adapted to be applied to the test piece, means for applying a force to said contact member to thereby distort said test piece, an indicator, means for rendering said indicator responsive to movement of said contact member, and means for rendering said indicator non-responsive to movement of said contact member when the force applied to said contact member reaches apredetermined value.

3. In testing apparatus of the character described the combination of a contact member adapted to be applied to a test piece, means for applying'a force to said contact member to thereby distort said test piece, an indicator, means responsive to said force for rendering said indicator responsive to movement of said contact member, and means for rendering-the indicator nonresponsive to movement of the contact member when the force applied to said contact member reaches a predetermined value;

4. In testing apparatus of the character described the combination of a contact member applying a force to said contact member to thereby distort said test piece, indicating means, means responsive to said force for rendering said indicating means efl'ective to register movement of saidcontact member, and means responsive to a predetermined value of said force for rendering the indicating means non-responsive to the movement of the contact member and for looking said indicating means in the position thereof corresponding with said predetermined value.

5. In testing apparatus of the character described the combination of a contact member adapted to engage a test piece, means .for applying force to said contact member to thereby distort said test piece, an indicator for measuring .distortion of said test piece, means for actuating said indicator, and means responsive to the force exerted bysaid force applying means for operatively connecting said actuating means with and disconnecting the same from said contact memher.

6. In testing apparatus of the character de-' piece, indicating means, means for operatively connecting said indicating means with said actuating means whereby the formeris adapted to be actuated upon movement of said impression member into said piece, and means for disconnecting said indicating means from said actuating means when a predetermined force is exerted by the latter on said impression member.

'8. In testing apparatus of the character described the combination of a frame, an impression member, a holder movable in said frame for pressing said impression member against a test piece, an indicator supported on said frame, a.

9. In testing apparatus the combination of an impression member, means for actuating said impression member to press the same into a test piece, an indicator, a member effectively connected to said indicator and adapted for engagement with said actuating means and to.b.e moved thereby to operate said indicator, means for releasably connecting the indicator operating member with said actuating means, and means responsive to a predetermined force exerted on said impression member by said actuating means to automatically move the indicator operating member out of engagement with said actuating means.

10. In testing apparatus the combination of an impression member, means for actuating said impression member to press the same into a test piece, an indicator, means effectively connected to said indicator and adapted for movement by said actuating means for operating said indicator, means for releasably connecting the indicator operating means with said actuating means, and electromagnetic means adapted to arrest movement or the indicator operating means, when the pressure applied to said impression member by said actuating means reaches a predetermined value.

1 1. In testing apparatus or the character described the combination of an impression member, means for actuating said impression member to press the same into a test piece, an indicator, 9, magnetizable member having operative connection with said indicator, means ro'r reieasably connecting said magnetizable member for movement. with said actuating means, a magnetarranged'to attract said magnetizable member to disconnect the latter from said actuating means, and means for energizing said magnet when the pressure applied to said impression member reaches a predetermined value.

12. In testing apparatus of. the character described the combination 01 'a contact member adapted to be applied to a test piece, a plunger arranged to move said contact member to thereby distort said test piece, means for applying an actuating force to said plunger, an indicator hav.--- ing an actuating member, an electromagnet .movable with said plunger and adapted-when energized to render said indicator actuating memberresponsive to movement of said contact member, and a switchresponsive to said actuating force for controlling the energizationv otsaid electromagnet. a 13.In testing apparatus of the character described the combination of a frame, an imprestract -said magnetizable mem inder to actuate said .Said pump inclu sion member, a holder movable in said frame for pressing said impression member against a test piece, an indicator supported on said frame, a movable control for said indicator, said control being of magnetic material, a magnet movable with said holder and adapted to attract said control to thereby connect the latter for movement with said holder, a stationary electromagnet adapted to attract said control to arrest movement thereof, and means for energizing said electromagnet when the pressure applied to said 14. In testing apparatus of the character described the combination of an impression member, means for actuating said impression member to press the same into a test piece, an indicator, a magnetizable memberhaving operative connection with said indicator, a magnet movable with said actuating means and arranged impression member reaches a predetermined value..

to attract said magnetizabie' member to thereby connect the latter for movement with said actuet adapted to. atr to thereby disconnect the same from said actuating means, and means, for energizing said'stationary magnet when the pressure applied to said impression member reaches a predetermined value.

15. In testing apparatus of the character described the combination of a. contact member adapted to be applied to a arranged to move said contact member to thereby distort said test piece, means for applying an actuating force to said holder, an indicator having an actuating member, an electromagnet arranged for movement by said holder and adapted when energized to render said indicator actuating member responsive to movement oi. said contact member, av stationary electromagnet adapted when energized to render the movable electromagnet ineffective, and switch means responsive to said actuating force for energizing said electromagnets insuccessiom v I 16. In testing apparatus vot'the character deating means, a stationary scribed the;combination of a, contact member.

sponsive-to said pressure fluid for energizing said electromagnets in succession. 7

1'1. In testing apparatus of the character described the combination of a contact member adapted to be applied to' a. test piece, a cylinder, a plunger in said cylinder for moving said contact member to thereby distort said test piece. a pump for supplying pressure fluid to said cylplunger, means for driving a clutch and-an electromagnet for actuat ng said clutch, an indicator having an actuating member, another. electromagnet arranged for movement by said plunger and adapted when energized to render said indicator actuating member responsive to movementfoi said contact member, a stationary electromagnet adapted when energized to render the movable electromagnet ineffective, and switch test piece, a holder 2,009,314 means adapted to be actuated in succession by said pressure fluid for controlling the energize.- tion of said electromagnets.

18. In testing apparatus of the character described the combination of a contact member adapted to be applied to a. test piece, a cylinder, a plunger in said cylinder for moving said contact member to thereby distort said test piece, a pump for supplying pressurefluid to saidcylinder to actuate said plunger, means for driving said pump including a clutch and an electromagnet for actuating said clutch, a circuit for said electromagnet including a normally closed switch, an indicator, means responsive to said pressure fluid for rendering said indicator responsive to movement of said contact member, means responsive-to a predetermined pressure value of said fluid for rendering the last mentioned means inefiective, and means adapted to be actuated by said pressure fluid for opening said normally closed switch.

19. In testing apparatus of the character de scribed the combination of a contact member adapted to be applied to a test piece, a cylinder, a plunger in said cylinder for moving said contact member to thereby distort said test piece,

a pump for supplying pressure fluid to said cylinder to actuate said plunger, means for driving said pump including a motor and a clutch for connecting said pump to said motor, an electromagnetic control for said clutch, a circuit for said electromagnetic control including a normally closed switch, an indicator, means responsive to said pressure fluid for rendering said indicator responsive to movement of said contact member,

means responsive to a predetermined pressure value of said fluid for rendering the last mentioned means inefiective, means adapted to be actuated by said pressure fluid for opening said normally closed switch, and means for delaying the actuation of the last mentioned means. I

20. In testing apparatus of the character described, the combination of a contact member adapted to engage a test piece, means for applying a force to said contact member to thereby distort said test piece, an indicator for registering distortion of said test piece, electromagnetic means for operatively connecting said indicator with and disconnecting the same from said contact member, means responsive to said force for controlling said electromagnetic means, control means for rendering said force applying means ineflective, and means for preventing actuation of the last mentioned control means until the control means for said electromagnetic means has responded to said force.

21. In testing apparatus of the character described, the combination of a contact member adapted to engage a test piece, means for moving said contact member to thereby distort said test piece including a piston and a cylinder for said piston, means for supplying pressure fluid to said cylinder, means for registering distortion of said test piece, electromagnetic means for connecting said registering means with and disconnecting the same from said contact member, a plunger adapted to be moved by said pressure fluid for controlling said electromagnetic means, means for controlling said fluid pressure supply means, a plunger for actuating the last mentioned control means, and meams associated with the first mentioned plunger for controlling the supply of pressure fluid to the second mentioned plunger.

22, In testing apparatus of the character dedistortion of'the test piece.

scribed the'combination of a contact member adapted to be applied to a test piece, means for applying a force to said contact member to thereby distort sald test piece including a piston and a cylinder for'said piston, means for supplying pressure fluid to said cylinder, means for controlling the supply of pressure fluid to said cylinder including an electromagnet, a manually operable switch in the circuit of said electromagnet and having a switch member adapted for movement from a released position to an operative position for energizing said electromagnet, and means cooperating with said switch member to prevent energization of said electromagnet until said switch member has first been moved to said released position.

2 3. In testing apparatus of the 1 character described the combination of a contact member adapted to be applied to a test piece, a movable holder for actuating said contact member to thereby distort said test piece, an indicator hav-.

-magnetic material, and a magnet movable with said holder and adapted to attract said control to thereby connect the latter said holder.

25. In testing apparatus of the character described the combination of a contact member for engagement with a test piece, means for applying a force to said contact member to thereby distort said test piece including a piston and a cylinder for said piston, means for indicating the extent of a portion of the movement of said contact member during the distortion of said test piece comprising an indicator'and an actuating member therefor, means for connecting said actuating member with said contact member for movement therewith after said contact member has moved through a portion 01' its stroke, and means for supplying pressure fluid to said cylinder at a substantially constant rate during the for actuation by 26.- In testing apparatus of the character described the combination of a contact member for engagement with a test piece, means for actuating said contact member including a piston and a cylinder for said piston, means for supplying.

pressure fluid, to said cylinder for causing an initial rapid movement of said contact member relative to said test piece, means fcrsubsequently supplying pressure fluidto said cylinder at a rate to cause relatively slow but substantially uniform movement of said contact member for distorting said test piece, means for indicating the extent of a portion of the movement of said contact member during the distortion of'the test piece comprising an indicator and an actuating member therefor, and means for connecting said actuating member with said contact member for movement therewith after said initial rapid movement.

-27. In testingapparatus of the character described the combination of a contact member for engagement with a test piece, means for applying a force to said contact member to thereby cylinder at a substantially constant rate during the distortion of the test piece, and means for rendering the pressure fluid'supply means ineffective when the pressure of the fluid reaches a predetermined value.

28 .In testing apparatus of the character describedthe combination of a contact member for engagement with a test piece, means for applying a force to said contact member to thereby distort said test piece including a piston and a cylinder for said piston, means for indicating the extent of a portion of the movement. of said contact member during the distortion of said test piece comprising an indicator and an actuating member therefor, means for connecting said actuating-member with said contact member for movement therewith after said contact member has moved through a portion of its stroke, a reciprocating pump for supplying motive fluid to said cylinder at a. substantially constant ratev but. un-- qder progressively increasing pressure during'the distortion 0! the test piece, and means rendered eflective for reversing the pump when the. pressure. of the fluid reaches a predetermined value.

' initial rapid movement of said 29. In testing apparatus of the character described the combination of a contact member for engagement with a test piece, means for actuating said contact member including a piston and a cylinder for said piston, means for supplying pressure fluid to said cylinder for causing an contact member relative to said test piece, means for subsequently supplying pressure fluid to said cylinder at a rate to cause relativelyslowbut substantially uniform movement 0! said contact member for distorting said test piece, means for indicating the .'.extent oi a portion oi-the movementoi said confor connecting said mem , tact movement therewith after said initial .ply .of pressure value.

having an actuating,

member during the distortion or said test piece comprising an indicator and an actuating member therefor, means for connecting said actuating member with said contact member for rapid movement, and means for interrupting the sup- I fluid to said cylinderwhen the pressure oi the fluid reaches apredetermined 30. In testing, apparatus of the character defscribed the combination" of a contact member adapted to be applied to a test piece, a movable holder for actuating said contact member to said test piece, fluid pressure I said'holder, an indicator 9. portionor its stroke indeactuating member, and means actuating member with said movable thrpugh pendently or said said, portion '0! its I hcldgfforgmovement therewith after said contact r has-moved throii'gh stroke, the last mentioned means being rendered effective in response to the fluid pressure. I

31. In testing "apparatus of the character de-'- scribed the combination of a contactmember adapted to be moved into engagement 'with'and to distort a test piece,-'a movable holder tor'actuating said contact-memben fluid pressure means ember, said holder being for actuating said holder, an indicator having an actuating member, said holder being initially movable independently of said actuating member, and means whereby said actuating member is caused to be responsive to the movements of said contact member after the latter has moved into engagement with said test piece, the last 1 extending adjacent said holder and adapted to be connected therewith, and means carried by said holder and automatically rendered effective for connecting the indicator actuating member with the holder substantially upon engagement of the contact member with the test piece, the last mentioned means being responsive. to the increase in the pressure of the .fiuid incident to said engagement. Y

33. In testing apparatus of the character described the combination of a contact member adapted to to distort a test piece, a movable holder for actuating said contact member, an indicator having an actuating member adapted to be efiectively connected by magnetic attraction for movement proportionately with said contact member, and an electromagnet adapted when energized to cause such magnetic attraction.

34. In testing apparatus of scribed the combination of'a contact member adapted to be moved into engagement with and to distort a test piece, a movable holder for actuating saidcontact member, an indicator having an actuating member adapted to be effectively connected with said holder by magnetic attraction, an electromagnet for producing such-attraction, and means'rendered effective upon engagement of said contact member withsaid test piece for energizing said electromagnet.

the character debe moved into engagement with and scribed the combination of a contact member adapted to be moved into engagement with and to distort a test piece, a holder movable in response to fluid pressure for actuating saidcontact'memher, an indicatorhaving an actuating member adapted to be effectively connected by magnetic attraction for movement proportionately with said, contact member, an electromagnet adapted when energized to cause such magnetic attraction,

.' and means for energizing the electro agnet including acontrol actuated by the n d pressure. 36. In testing apparatus of the character described the. combination of a contact member adapted to be moved into engagement with and to distort a test piece, a holder movable in response to fluid pressure for actuating said contact member, anindicator having an actuating member adapted to be effectively connected by magnetic attraction for: movement proportionately with said contact member, an electromagnet adapted adapted to be actuated by an increase in the pressure or the fluid incident to engagement 0! the p contact member with the test piece. 37,- In testing apparatus of the character described the combination ofa test piece suppoit,

a movable relative to said support 

